JPH01254818A - Vibration detecting device - Google Patents

Abstract

PURPOSE:To perform high-accuracy vibration detection by providing a detection arm which is so energized as to abut on the tip of a detection pivot at all times and a noncontact potentiometer which transduces the motion of an inductor corresponding to the rotation of the detection arm into an electric signal and outputs the electric signal. CONSTITUTION:The detection arm 23 is energized by a spring, etc., so as to abut on the detection pivot 22 at all times. Then when a body to be detected begins to vibrate, the inductor of the non-contact potentiometer 24 varies through the pivot 22 and arm 23. At this time, the arm 23 abuts on the pivot 22, so even when the vibration of the body to be detected is not only in the direction of vibration to be detected, but includes horizontal vibration together, the vibration displacement in the object vibration direction is securely detected. Further, the electric signal of frequency corresponding to the vibration is amplified and an HPF cuts off the DC component, so even if a rotary drum 17 to be detected and an external tank 16 fluctuate vertically owing to the amount of the internal water, etc., the vertical vibration in the position shifting state is accurately detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration detection device, and particularly to a vibration detection device that uses a non-contact potentiometer to detect excessive vibration of a subject in a predetermined direction.

[Prior Art] In various types of equipment, when a component part of the equipment vibrates with an acceleration or displacement amplitude exceeding a predetermined level, there is a risk that equipment failure or noise may occur.

For this reason, M types of vibration detection devices are used as devices for quickly detecting vibrations and emitting signals to stop the vibrations.

Figure 3 shows a vibration detector installed in a drum-type washing machine disclosed in Japanese Patent Publication No. 58-24155.
This vibration detector is a vibration detector that detects excessive vibration of a rotating drum of a drum-type washing machine and issues a signal for controlling the speed of the rotating drum when the vibration occurs.

In the figure, (1) is a vibration detector, and this vibration detector (
The vibration detection lever (2) protruding from the side wall of the washing tank (1) is installed at a position opposite to the side wall of the washing tank (3) which houses a rotating drum inside, and detects vibrations exceeding a certain amplitude in the washing tank (3). In this case, the vibration detection lever (16) is pushed upward against the spring force of the spring (4). One end of this detection lever (2) pushes a movable contact piece (5) of a switch S1 provided in the drive detector (1). Due to this push-up operation, the contact point of the movable contact piece (5) moves from the contact point Bl of the fixed contact piece (6) to the contact point At of the fixed contact piece (7). Here, since a spring (8) is provided at the tip of the movable contact piece (5) in the longitudinal direction J, this spring (8)
) passes through the dead center, the movable contact piece (5) moves from contact B [to AI
When switched to (R), it will not return unless force is applied from the -L direction.

Further, the vibration detection lever (2) returns to its original state by the spring force of the spring (4) when the abnormal vibration of the washing tub (3) stops.

That is, this vibration detector (1) sends a signal to a control circuit (not shown) when the movable contact piece (5) is switched to the contact Al side, and controls the speed of the rotating drum in the washing tank (3). This is to reduce vibration.

Also, near the vibration detector (1), there are cams (10), (11) and (1) attached to the timer shaft (9).
2) is provided, and the movable contact piece (5) is the contact point (A1).
Rotation is started when the switch is switched to , and after a predetermined period of time, the return rod (13) is suddenly pushed downward to return the movable contact piece (5) to its original state.

[Problems to be Solved by the Invention] However, if the object whose vibration is to be detected changes its position when being vibrated, for example, the laundry receptacle of a drum-type washing machine, etc. Since an object contains a large amount of water, its total amount of tlln increases. Therefore, when the weight of the laundry receptacle, which is normally suspended by a spring or flexibly supported at the bottom, shifts downward, the iQ becomes lighter as the laundry is dehydrated, and its position moves upward. .

Therefore, in the case of a subject whose position changes in this way,
Since the vibration detection lever (5) is fixed within the vibration detector (1), there is a problem in that it cannot always accurately detect the amount of vibration.

That is, when the laundry receiving tub (3) is sunk downward in the figure, there is a problem that the detection range of abnormal vibrations by the vibration detection lever (2) is exceeded, and vibration detection cannot be performed.

In addition, in the case of using the above-mentioned conventional vibration detector, the washing tray 1
+”i When (3) vibrates including horizontal vibration, the washing tub (3) is separated from the vibration detection lever (2), so the vibration in the detected vibration direction can be detected quickly and accurately. Furthermore, according to this device, it is necessary to provide a vibration detection lever and a return rod that are biased by multiple contacts and springs, which requires a large number of parts and a complicated structure. There was a problem that.

Purpose of the Invention The present invention has been made to solve the above problems.
It is an object of the present invention to provide a vibration detection device having a simple structure and capable of accurately detecting vibration in a desired vibration direction to be detected, regardless of positional deviation of an object.

[Means for Solving the Problems] In order to achieve the object ``-2, the vibration detection device according to the present invention has a vibration detecting device fixed to the object coaxially with the direction of vibration to be detected so as to vibrate together with the vibration of the object. A detection pivot, a detection arm that is rotatable about one end as a fulcrum and is biased so that the other end always comes into contact with the tip of the detection pivot, and an inductor to which the fulcrum side end of the detection arm is fixed. and a non-contact potentiometer having a detector provided in a non-contact manner on the inductor, the non-contact potentiometer converting vibrations transmitted from the detection pivot to the detection arm into an electrical signal and outputting the electrical signal, and this potentiometer. an amplifier that amplifies the signal from the 71i signal from the amplifier, a high-pass filter that removes the DC component and low-frequency vibration component of the 71i signal from this amplifier and outputs only the electrical signal with a predetermined frequency or higher, and a high-pass filter that converts the signal from the high-pass filter to a reference level. A comparator that outputs a vibration generation signal when a vibration with an excessive amplitude exceeding a reference level is generated compared to the signal, and a pulse generator that emits a predetermined pulse signal when receiving the excessive vibration generation signal from this comparator. It is characterized by the provision of means.

[Operation] According to the above configuration, the vibration of the subject is transmitted to the detection arm by the detection pivot fixed to the subject. One end of this detection arm, which is the fulcrum side end, is attached to the inductor of the non-contact potentiometer, and is rotated about the fulcrum side end by the vibration of the detection pivot in the detected vibration direction.

By rotating this arm of the non-contact potentiometer:
A-only moves in response to the vibrations of the subject. The non-contact potentiometer outputs an electrical signal at a frequency corresponding to the vibration of the subject based on the movement of the inductor. This 1-high signal is amplified by an amplifier, and then a high-pass filter cuts off a direct current component and a low frequency vibration component.

Next, the voltage change signal with a predetermined frequency or higher that has passed through the high-pass filter is sent to the comparator, which compares this signal with the reference level signal and outputs an excessive vibration generation signal if it is higher than the reference level signal. do. This vibration signal is supplied to the pulse generating means, and the pulse generating means outputs a detection pulse having a predetermined pulse width.

In addition, even when the object is vibrating not only due to vibration displacement in the direction of vibration to be detected (also due to vibration displacement in other directions), the above-mentioned arm is always in contact with the detection pivot. Only the vibration component in the vibration direction can be extracted accurately.

Therefore, the high-pass filter can ignore slow vibrations that do not require control, and the comparator can also ignore vibrations with a small vibration width that do not require control.
This makes it possible to quickly detect only large excessive vibrations.

Furthermore, even if there is a positional shift in the detected vibration direction of the object, the DC component is blocked by the above-mentioned high-pass filter, so even if the reference level of vibration displacement deviates significantly due to the positional shift, the displacement It is possible to cancel the influence of vibration caused by vibration, and the vibration of the object to be examined can always be detected accurately.

The comparator and the pulse generating means can generate a detection pulse when vibration exceeding a predetermined level occurs, and it is possible to control the vibrating part of the subject using this detection pulse.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

In this example, the present invention was used to detect the vibrations of the rotating drum and outer tub of a drum-type washing machine. Since vibrations are more likely to lead to noise generation and equipment failure, it is necessary to accurately and quickly detect vibrations in the detected vibration direction and control the speed of the drive unit.

FIG. 1 is a schematic diagram of a drum-type washing machine showing the installation of a vibration detection device according to the present invention, in which a detachment 9 (16) is installed in a casing (15).

A rotary drum (17) is rotatably supported inside the outer tank (16), and a rotating shaft (18) of the rotary drum (17) projects outward from the side wall of the outer tank (16). It is coupled to a rotating shaft (20) of a drive motor (19) by a belt (21).

The rotating drum (1) is driven by the drive motor (19).
7) is rotated during washing or drying.

The outer tank (16) is flexibly supported within the casing (15) using a spring or the like, and is supported by a rotating drum (16).
If shaking occurs during the rotational drive in step 7), it will vibrate along with this shaking.

Therefore, it is preferable that the vibration detection device is provided with a member for transmitting vibrations to the drive motor (19) fixed to the outside (16) or the outside 1ff (16). A detection pivot (22) is provided at the bottom of the outer tank (16) in the vertical direction, which is the direction of vibration to be detected, and a detection arm (23) is attached to receive vibration from this detection pivot (22) in the direction of the detected vibration. A non-contact potentiometer (24) is installed at the bottom of the casing (15).

FIG. 2 is a schematic diagram of the vibration detection device according to this embodiment, in which the side of the detection arm (23) is in contact with the detection pivot (22) fixed to the outer tank (16). The sensing arm (23) has its fulcrum side end (23a) fixed to the inductor of the non-potentiometer (24). The detection arm (23) is biased toward the detection pivot (22) by a spring or the like so that it can always come into contact with the detection pivot (22). Therefore, the detection arm (23) rotates following the vibration of the detection pivot 1-(22).

FIG. 3 is a diagram showing the circuit configuration of the embodiment, and the non-contact potentiometer (24) is shown as an equalization circuit in the diagram, but in reality, a non-contact potentiometer using a Hall element is used. It will be done.

The fulcrum side end (23a) of the detection arm (23) is attached to the inductor (24a) of the non-contact potentiometer (24), and the detection arm (23) receives vibration from the detection pivot (22) and rotates. By moving the inductor (24
a) moves, and as a result, a voltage change signal with a frequency corresponding to the vibration of the subject is transmitted to the amplifier (25) via the resistor R3.
Output to the negative terminal of. The positive terminal of the amplifier 5 (25) is connected to the intermediate connection terminal of the voltage dividing resistors R1 and R2 connected to both ends of the non-contact potentiometer (24).
connected via. This amplifier (25) amplifies the voltage of the electrical signal from the non-contact potentiometer (24), and the amplification factor is determined by the ratio of resistors RQ/R3.

The amplified electrical signal then passes through a high pass filter (26) formed by capacitor c1 and resistor R7. Here, the electrical signal is connected to capacitor CI and resistor R7.
The DC component and low frequency vibration component are blocked by a time constant determined by the product of , and only electrical signals with a predetermined frequency or higher that are determined to be abnormal vibrations are sent to the next stage.

The electrical signal from the high-pass filter (26) is supplied to the negative terminal of the comparator (27) via a resistor R9. The positive terminal of the comparator (27) is connected to the intermediate terminal of a resistor R8 connected in series with the power supply and a variable resistor Vrl via a JJu resistor RIO.

That is, the electrical signal from the high-pass filter (26) is compared with a voltage divided by the resistance ratio of resistor R8 and variable resistor Vrl. Here, the comparator (27) outputs a high voltage (Hl') when the electric signal is lower than the reference voltage, and outputs a low voltage (Lo) when it is higher. The reference voltage level can be changed and set using a variable resistor Vrl.

Figure 4 shows the voltage change signal output from the non-contact potentiometer (24) via the amplifier (25) in response to the vibration of the subject, with the vertical axis representing voltage and the horizontal axis representing time.
A reference voltage level is indicated by a dashed line (100).

In the high-pass filter (26), the region A portion of the vibration region Z is cut.

Therefore, a portion of the signal region Y having a predetermined amount of frequency and large amplitude is sent to the next stage.

And, on the output side of comparison 5 (27), there is a trigger IC (2
8) is connected, and this trigger IC (28) generates a detection pulse of a predetermined pulse width when the signal from the comparator (27) changes from (Hl) to (Lo). This pulse width is set by the size of a time constant represented by the product of resistor R12 and capacitor C2. According to this embodiment configured as described above, when the subject starts to vibrate, the inductor of the non-contact potentiometer (24) changes via the detection pivot 1- (22) and the detection arm (23). do. At this time, the detection arm (23) is always in contact with the detection pivot (22), so even if the vibration of the object is mixed not only in the detected vibration direction but also in the water direction, the detection arm (23) is always in contact with the detection pivot (22). It is possible to reliably detect vibration displacement in the vibration direction.

In addition, an electrical signal with a frequency corresponding to this vibration is transmitted through an amplifier (
After being amplified by a high pass filter (26)
), 111 streams are cut, so even if the rotating drum (17) and outer tank (16), which are the objects to be inspected, fluctuate in their vertical position due to internal water volume, etc.
It is possible to accurately detect vertical vibrations while the position is changing.

Further, since low frequency vibrations are also cut by the high pass filter (26), it is possible to ignore low frequency vibrations that do not particularly require control of the driving section of the washing machine.

When a vibration of a magnitude that requires controlling the drive section of the washing machine occurs, that is, when the signal is a voltage change larger than the base q voltage level in the comparator (27), the trigger IC is activated. A detection pulse can be output from (28).

This detection pulse activates a circuit for controlling the driving section of the washing machine, making it possible to control the washing machine so that vibrations are reduced.

The mounting location of the detection pivot 1-(22) is not limited to the bottom of the outer tank (16);
For example, it is also possible to detect the occurrence of abnormal vibrations by attaching it to the shaft of the drive motor (19) and detecting its vibrations.

[Effects of the Invention] As explained below, the vibration detection device according to the present invention can accurately and quickly detect abnormal vibrations in the direction of vibration to be detected, regardless of vertical movement of the subject. When this abnormal vibration is detected, it is possible to immediately issue a signal to start controlling the drive unit of the subject.

Furthermore, in the present invention, since the vibration of the test object is converted into an electric signal by a non-contact potentiometer, there is no wear of the contact parts due to vibration, the life is long, and highly accurate vibration without noise is generated. Detection can be performed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing how the vibration detection device according to the present invention is attached to a drum-type washing machine, FIG. 2 is a schematic configuration diagram showing the mechanical configuration of the embodiment, and FIG. 3 is the electrical circuit configuration of the embodiment. 4 are electrical signal diagrams corresponding to vibrations of the subject, and FIG. 5 is an explanatory diagram showing a conventional vibration detector used in a drum-type washing machine. In the figure, (22) is the detection pivot, (23) is the detection arm, (23a) is the fulcrum side end, (24) is the non-contact potentiometer, (24a) is the inductor, (25) is the amplification 2u, (26) is the ) is a high-pass filter, (27) is a comparator, and (28) is a trigger IC. In the figures, the same reference numerals indicate common elements.

Claims (1)

[Claims] (1) A detection pivot fixed to the object coaxially with the vibration direction to be detected so as to vibrate with the vibration of the object; and a sensing pivot whose one end side is biased so as to always come into contact with the tip of the detection pivot. a detection arm that rotates about its other end as a fulcrum due to vibrations in the vibration direction; an inductor to which the fulcrum portion of the detection arm is fixed; and a detector provided in close proximity to the inductor in a non-contact manner; a non-contact potentiometer that converts the movement of the inductor corresponding to the rotation of the detection arm into an electrical signal and outputs it; an amplifier that amplifies the signal from the non-contact potentiometer; and a DC component and low voltage of the electrical signal from the amplifier. A high-pass filter that removes frequency vibration components and outputs only electrical signals with a predetermined frequency or higher, and detects excessive vibration in the direction of the detected vibration of the object by comparing the signal from the high-pass filter with a reference level signal. A vibration detection device comprising: a comparator; and pulse generation means for outputting a detection pulse having a predetermined pulse width based on an excessive vibration detection signal from the comparator.